g/cm3), uniformly occupying empty space and having negative pressure (acting repulsively), while the mass–energy of dark matter makes 26.8%, ordinary (baryonic) matter contribute 4.9%, plus the rest components, such as neutrinos and photons, giving in a negligible amount. Other observations are figuring a universe made up 71.3% of dark energy and 27.4% of a combination of dark matter and baryonic matter.

Whatever, knowing the nature of dark energy and dark matter, as the fundamental cosmological constant and quintessence, how it all interacts with the ordinary matter, as subjected to numbers in terms of extension, change, force, mass, energy and radiation, is most critical for a single theory of the universe

Since, ultimately, four or five main force-interactions, strong, electromagnetic, weak, gravitational, and dark, would combine into the proto force, the Faraday’s universal force, in the ToE, like as in a super string theory, at the beginning of the universe (up to 10^>-43 seconds after the Big Bang), the four fundamental forces were once a single fundamental force. One might add up here a hypothetical fifth fundamental force of nature, “dark force of dark energy and matter”, theorizing as a force pushing the galaxies aside accelerating the expansion of the universe up to half of the age of the universe (7,5 billion years) (Krasznahorkay, A. J. et al. Physical Review Letters 116, 042501 (2016)).

That might implies that all the fundamental force-interactions might come out as different manifestations of the prime natural force, the prime mover, the first cause of all changes in the universe, including the original event of the hypothetical Big Bang, the singularity referring to the early hot, dense state considered the "birth" of the universe.

So, the final cause of natural science of physics is, in the most general way, to formulate a system of comprehensive principles uniting and explaining all physical phenomena, physical causes and forces, mechanical, gravitational, thermal, electromagnetic, and nuclear forces, weak and strong.

The very universality and convertibility of natural forces and the reversible relationships of physical causes and thence their inherent integrity inspired Faraday, Maxwell and Einstein to seek unification of all the physical processes by a single set of physical laws.

The very universality and symmetry of interactions of natural forces, or reversibility of physical processes, has inspired great physical minds to discover the basic laws of physics, as symmetry principles and conservation laws, and formulate the quantum theory and relativity principle, as Einstein’s matter-energy relationship or space-time relationship.

The very universality of conservation laws of interactions of natural forces, as gravity, nuclear interactions, or electromagnetic interactions, has inspired to discover one of the basic principles of nature, that the laws of physics remains valid in all places and times in the universe. Regardless of all the changes taking place with physical systems, of any scale and complexity, basic physical quantities, as mass, momentum, mass-energy, or baryon number, remain unchangeable or constant.

But, regardless that the great ideas of forcible interactions, process reversibility, energy and effect convertibility have been guiding physical science since its origination, neither has been properly formulated as the fundamental principle and general law of nature and the universe.

To contribute, we introduced the concepts of